Apparatus for conditioning a flow of fluid



Jan. 13, 1970 A. CHALOKA 3,489,204

APPARATUS FOR CONDITIONING A FLOW OF FLUID Filed Feb. 8, 1968 4 Sheets-Shet 1 N SI N am) S Jan. 13, 1970' CHALOKA 3,489,204

APPARATUS FOR CONDITIONING A FLOW OF FLUID Filed Feb. 8, 1968 4 Sheets-Sheet 2 I N VEN TOR Aways Cwno w Jan. 13, 1970 A. CHALOKA APPARATUS FOR CONDITIONING A FLOW OF FLUID 4 Sheets-Sheet 5 Filed Feb.

5 w/ Am M d a wow w INVENTOR. fl/vzweh/ Cwcoefl Jan. 13, 1970 cHALQKA 3,489,204

APPARATUS FOR CONDITIONING A FLOW OF FLUID Filed Feb. 8, 1968 4 Sheets-Sheet 4 l 52a 4 7o 52; BY W 8 ANOA Cxmaom United States Patent 3,489,204 APPARATUS FOR CONDITIONING A FLOW 0F FLUID Andrew Chaloka, Clark, N.J., assignor to Aero-Flow Dynamics, Inc. (The Wing Co. Division), Linden, N.J.,

a corporation of New York Filed Feb. 8, 1968, Ser. No. 704,162 Int. Cl. G05d 23/00; F28f 27/00, 27/02 US. Cl. 165-35 18 Claims ABSTRACT OF THE DISCLOSURE Integral face and bypass type air heater unit having identically configured but symmetrically arranged damper wings projecting outwardly in respective rows thereof at opposite ends of the unit for reversibility of air flow through the unit; damper control bars for concurrently pivoting all laterally adjacent dampers in alternately opposite directions between positions fully opening and fully closing the alternately adjacent face passages and bypass passages; damper Wings have angular configuration per specification; all damper Wings mounted on a row of laterally spaced apart single shafts which define said face and bypass passages; damper control means includes concurrently and oppositely pivotable levers per specification.

This invention generally relates to apparatus such as a heater of the type used to heat or otherwise condition the temperature of a fluid, such as air or the like, which is flowing therethrough. More particularly, the invention relates to the construction and arrangement of the movable dampers as are incorporated in such apparatus for selectively proportioning the total fluid flow between certain passages of the unit which contain fluid conditioner tubes, and respectively adjacent bypass areas which do not contain such tubes, so that the temperature of the flowing fluid may be thereby modulated. In view of the alternate conditioner-passage and bypass-passage arrangement, and the integral disposition of all such passages within an assembled unit through which all of the air supply flows, such apparatus is sometimes referred to as an integral face and bypass unit. In this context, face refers to the respective faces of the fluid conditioner tubes or coils.

The invention in its broader aspects may have other uses as will be apparent once its principles are understood. However, it was made while attempting to improve air heater units of such particular type, and therefore will be described in such connection.

Perhaps the most successful type of integral face and bypass heater heretofore known is that shown in Horn et al. US. Patent No. 3,107,724. That heater arrangement provides individual separating walls or partitions dividing each face (i.e., heating tube) passage from its adjacent bypass (i.e., open) passages; pivotable air inlet dampers in the form of curved airfoil sections respective ly straddling these passage divider partitions such that concurrent movement of the dampers in alternately opposite directions opens all of either the face passages or the bypass passages and proportionately closes the other; and pivotable air outlet dampers in the for-m of flat 3,489,204 Patented Jan. 13, 1970 dampers mounted centrally of only the face passages for closing the same at the opposite end of the heater when the inlet ends of the face passages are fully closed so as to avoid so-called temperature override or leakage heating of the bypassing air under such operating condition. As pointed out in that patent, the Horn et al. heater provides a constant and minimum resistance to air flow regardless of the modulating position of the dampers, and high efliciency as regards heat transfer, heat isolation, and heat modulation control. However, it is not adaptable to reversible air flow systems since it performs well in one direction of air flow only, and is somewhat expensive to manufacture in view of its inclusion of the air passage separator walls, the necessarily different types of dampers at its respective air inlet and outlet ends, and the somewhat complicated damper control linkages and arrangements which must be provided.

The present invention contemplates a similar air stream heater whose performance characteristics are equal to or better than those of the heater shown by Horn et al., but one which in any event is less expensive and more convenient to build and maintain, and which is fully reversible operation, i.e. the air stream to be heated may enter from either end of the heater with no difference in heater performance. In particular, it is proposed to provide standardized dampers of but one damper configuration on both the inlet and the outlet ends of the heater so that, for example, fabrication of the differently configured and installed outlet dampers of the Horn et al. heater are eliminated. Such damper standardization further contemplates that the cross-sectional configuration of all of the individual damper wings will be identical, it being only necessary to mount the alternately adjacent damper wings in inverted position to achieve the contemplated damper action as will be described. Manufacturing costs will therefore be reduced by eliminating the fabrication of otherwise needed components, and further, by simplifying the linkage sys tem for controlling the positioning of the dampers, Type correspondence between the inlet and outlet dampers also effects a reduction in the necessary overall depth of the heater unit, so that it is more compact. Moreover, in addition to aflording full reversibility of the heater, the contemplated construction also eliminates the need for fixed separator partitions between the respective face and bypass passages of the heater, and the cost of their fabrication and installation is therefore avoided. Additionally, the configuration of the individual damper Wings is such that the air flow smoothly enters and leaves all of the referred to passages, regardless of the positioning of the Wings. The construction and arrangement adapts itself to heater units of any size, and it will be found that such units are lighter in weight than the comparable Horn et al. heater units.

Regarding prior damper arrangements in integral face and bypass type heaters other than that shown in the Horn et al. patent, applicant is aware of German patent application No. 1,093,373, published Dec. 1, 1960, which was an application for a patent of addition to German Patent 888,761, which has also been considered. However, it will be appreciated that neither these nor any other previously known heater or damper arrangement will afford the advantages of the present invention.

Briefly describing the invention in its preferred embodiment, a plurality of vertically disposed and laterally rpaced apart banks of heater tubes are mounted between lpper and lower steam (or hot water) headers of the aeater unit. The lateral spacing apart of the tube banks across the width of the heater frame generally defines the respectively alternate so-called face passages through the :ube banks, and bypass passages between the tube banks. However, the respective face and bypass passages are nore definitely defined by the dampers themselves, at 30th the inlet and outlet ends of the heater, which control the quantity proportioning of air flow between the face and bypass passages. Considering any tube bank of the lieater and its adjacent bypass passages at either side there- )f, the quantity of air permitted to flow into the tube bank as compared with the quantity of air permitted to flow Into the bypass passages is controlled by a pair of inlet dampers in a so-called clam shell arrangement with fespect to each other, each damper of the pair being situited on the side of the tube bank which is laterally opposite from the other and mounted for pivotal movement on a correspondingly situated vertical shaft which is aligned within the centerline plane of the heater. That is, as the dampers of the pair are pivoted on respective axes on laterally opposite sides of the tube bank and in fespectively opposite directions so that they move toward each other, the quantity of air permitted to flow through ihe heater tubes is diminished and the quantity of air permitted to flow through the laterally adjacent bypass passages is concurrently and proportionately increased. An oppositely disposed symmetrically operated pair of )utlet dampers is provided for similarly and concurrently :losing the downstream or outlet end of the tube bank, :ach of the pair of outlet dampers being pivotably mounted espectively on the same pivot shaft as that one of the nlet dampers which closes the corresponding half of the :ube bank on the upstream end of the heater. Thus, four ndividual dampers or wings are associated with anytube aank, the four being mounted on but two pivot axes or shafts situated midway of the depth of the heater respeciively at the laterally opposite sides of the tube bank, and )perating as respective pairs of dampers at the inlet and )utlet ends of the heater unit. All of the four dampers iave the same configuration when manufactured and are :herefore interchangeable with each other by the simple :xpedient of inverting every other wing as the group is nounted in adjacent relation across the inlet and outlet :nds of the unit. That is, each damper has a bend along ts length providing angular configuration in cross-section lLlCh that it serves, in conjunction 'with the then sy-mnetrical shapes of both its laterally adjacent dampers to fully close either the face passage or the intervening by- )ass passage with which it is associated, depending upon the position of the dampers. Moreover, at all times durng heater operation, the two dampers which are mounted )n the same pivot shaft on the same side of a tube bank Ione an inlet damper and the other an outlet damper) .ogether provide partitioning between that side of the .ube bank and its adjacent bypass passage.

The outwardly projecting free end of each damper blade )r wing includes a second bend along its length, in the :ame direction as the previously referred to bend of the ving, providing a flange portion which smooths the air low into the face passage with which the wing is asso- :iated. Considering any pair of damper wings which close either the inlet or the outlet end of a face passage, these lange portions together define a triangular-shaped zone, vhose apex faces inwardly, between the pair of wings vhen in the closed (i.e., abutting) position, which zone tccommodates a metal sealer strip of similar triangular- .haped cross section and which is attached to only one f the wings of the damper pair. Alternatively, the sealer ltrip may be circular or rod-shaped in cross section, as vill be seen. The sealer strip more effectively seals the nlet end of any face passage when it is intended to be fully closed, thus preventing virtually any flow of air through the passage, and also eliminates the referred to temperature override at the outlet end of the passage.

In an alternative embodiment, the outer end of each damper wing has the cross-sectional configuration of a rectangular parallelogram, the blade thus being characterized as tubular. The wing is hinged along its inner end portion which is actually an extension of a slant edge of the parallelogram at one of its acute-angled corners, the wing pivot axis being within the transverse centerline plane of the heater unit as in the preferred embodiment. The shape of the parallelogram is such that the opposite slant edge surface cofacingly abuts the symmetrical, corresponding surface of the'wing which is pivoted at the laterally opposite side of the face passage when the face passage is intended to be fully closed. When the damper wing is pivoted oppositely to its position closing the adjacent bypass passage, the surface formed by the outermost of the other parallel edges of the parallelogram cofacingly abuts the symmetrical, corresponding edge surface of the comating wing at the laterally opposite side of the bypass passage. These interfacing surface relationships of the damper pairs in both their respective positions fully closing either a face passage or a bypass passage virtually seal the closed passages against air leakage therethrough. Moreover, the tubular shape of each damper wing, which may or may not be filled with insulating material, avoids heat conduction therethrough when the face passages of the heater are intended to be fully closed.

The novel damper arrangement and construction as will be described facilitates the attachment and arrangement of the damper control rods which are necessary for their operation. In particular, it is found that simple pivot connections of the rods may be made to each damper, rather than providing respective universal ball joint connections at each damper as heretofore believed necessary to avoid any possible jamming of the damper wings and rods during movement of the dampers. Moreover, the frictional resistance of the substantial number of such ball joint connections has been eliminated, and therefore the damper mechanism of the present invention requires considerably less power to operate. Thus, a smaller size damper operating motor or motors may be used. In fact, it has been found that only one motor is required to operate all of the dampers of the very large heater unit as will be described in view of such reduced power requirements, although two might be employed.

These and other objects, features and advantages of the invention will become more fully apparent from the following detailed description of a preferred embodiment thereof, when taken together with the accompanying drawings, in which:

FIGURE 1 is a front elevation of an integral face and bypass heater unit in accordance with the invention, a number of its heater tube banks being omitted for clarity;

FIGURE 2 is an enlarged and fragmentary plan View in cross section as seen from line 2--2 in FIGURE 1, to illustrate the heater dampers in their face-passage open positions, and also in positions in which both the face passages and bypass passages are partially open;

FIGURE 3 is a view similar to FIGURE 2, but showing the heater dampers in their face-passage closed positions;

FIGURE 4 is an enlarged and fragmentary side elevation in cross section of the heater unit as seen from line 44 of FIGURE 1;

FIGURE 5 is a fragmentary plan view in cross section of a damper pair incorporating a modified form of sealer strip;

FIGURES 6 and 7 are fragmentary plan views showing an alternative damper construction in two positions thereof;

FIGURE 8 is an enlarged and fragmentary front elevation further illustrating the damper control linkages of the heater unit of FIGURE 1;

FIGURE 9 is a somewhat enlarged and fragmentary cross-sectional plan view of the FIGURE 8 illustration; and

FIGURE 10 is a fragmentary side elevation, to the scale of FIGURE 9, of the FIGURE 8 and FIGURE 9 illustrations.

Referring first to FIGURES 1 and 4, an integral face and bypass heater unit in accordance with the invention is generally indicated by reference numeral 11. The heater is intended for conventional mounting within and transversely across a duct or the like (not shown) for modulated heating of a moving air stream which flows through the duct responsive to the action of a blower or rotating fan (not shown) which is usually mounted in the duct either upstream or downstream from the heater unit 11. Although the illustrated embodiment is intended to heat air, it will be understood that apparatus in accordance with the invention might also be used for modulated cooling of a moving air stream, and that fluids other than air might flow through the apparatus to be heated or cooled. Accordingly, considering its possible broader applications, a unit such as the unit 11 may be generally referred to as fluid conditioning apparatus or the like, although the unit being described is specifically an air heater.

The air duct within which the heater unit 11 is to be mounted should have cross-sectional size and shape, either rectangular or square, corresponding with that of the heater unit frame, which is generally designated by reference numeral 12 and which is formed by bolting its vertical channel-iron side elements 13, 14 between its horizontal top element 15 and horizontal bottom element 16, the latter being similarly of channel-iron, as shown. Diagonal 45 steel bracing 17 is welded in place as indicated in FIGURE 1, the bracing being included on both of the opposite ends 18, 19 (FIGURE 4) of the frame for stiffening purposes. For further stiffening of the frame structure, the channel-shaped elements 13, 14, 15 and 16 have respective inwardly turned flanges 13a, 14a, 15a, 16a along their outwardly facing peripheries, as shown more clearly in FIGURE 4. Bolted in place at opposite s1des of the bottom of the frame 12 is a pair of mounting feet 20 for mounting a steam or hot water header as will be described. A support channel 21 extends the width of the frame at its underside (FIGURE 4) between the angleiron feet 20. The top of the frame 12 mounts a similar pair of header mounting feet 22, which are similarly of angle-iron, bolted in place as shown.

As an example of the size of the heater unit 11, its frame 12 may nominally measure nine feet (9) in width between its vertical side elements 13, 14, and either four feet (4') or eight feet (8') in height between its top and bottom elements 15, 16 depending upon its particular application. Of course, the unit may be made considerably smaller, or even larger, as circumstances require.

Referring briefly to FIGURES 2 and 3, it will be understood that within its frame 12 the heater unit 11 has a plurality of vertically extending and alternate heater or face passages 23 and open or bypass passages 24, which are defined by the respective, laterally spaced apart locations of the fixed vertical shafts 25 (attached between the top and bottom frame elements 15, 16) on which the pivotable, vertically extending damper wings 26, 27 and 28, 29 are mounted. In FIGURE 1, only the face passages 23 show clearly, since the bypass passages are therein indicated as being closed by the damper wings 28, 29 (and 26, and 27, not shown in FIGURE 1) as in the FIGURE 2 showing. FIGURE 3 more clearly illustrates the bypass passages 24, which as there shown have been opened by repositioning of the damper wings 26, 27 and 28, 29, as will be more fully explained.

The face passages may be referred to as fluid conditioning passages because they contain appropriate means for conditioning the temperature of the fluid which flows therethrough. For example, refrigeration coils or the like (not shown) could be disposed within each face passage 23 for the cooling of air or other flowing gas, if such were desired. However, in the air heater unit 11 being described, a vertically extending heater tube bank 30 is mounted within each face passage 23. Each tube bank 30 includes four parallel heater tubes 30a, each tube being of copper material and having a numerous plurality of rectangular-shaped, surrounding stainless steel fins 30b attached, as by clamping, in closely spaced apart relation along its length between the top and bottom frame elements 15, 16 for good dissipation and transfer of the heat emanating from the tube.

As illustrated in FIGURES 5-7, each tube bank 30 may additionally include attached vertically extending tube bafiles 300 of sheet metal or the like and having laterally projecting web portions 30d which are locked in place by the shafts 25 at the respective sides of the tube bank as shown, in instances where the pivotable damper wings 26-29 are fitted only loosely on their respective shafts, or otherwise permit substantial heat filtration into the adjacent bypass passages 24 which are intended to remain cool. However, as generally indicated in FIG- URE 4, each of the damper wings 26, 27, 28 and 29 of the preferred embodiment is mounted on its associated shaft 25 by two pivot hinges 31 (at top and bottom locations along its length, only the bottom hinge being shown), and each has appropriate filler stripping 32 of thin and soft metal material, such as l6-gauge cold rolled steel, attached as by spot welds 32a along the portions of its length which are intermediate its hinges. The stripping 32 is hammered to fit closely but slidably against the shaft 25 such that the damper wings themselves provide adequate heat-shielding. Thus, the tube bafiles 30c are not required in the preferred embodiment, or in other instances where the heat-shielding afforded by the damper wings themselves is considered adequate.

As is well known, to avoid differences in pressure drop and air velocity through the alternate passages, the actual air passage area through each of the face passages 23 and bypass passages 24 must be equal to each other, and therefore each face passage 23 is wider than any bypass passage 24 by an amount which accounts for the area of obstruction to air flow as is presented by the tubes 30a and fins 3012. Thus, it will be understood that the air volume or rate of flow capacity through all ten of the face passages 23 as shown in FIGURE 1 is equal to that through the ten bypass passages 24 (considering the half-sized bypass passages at the respective sides of the frame .12), when they are respectively fully open, and such is determinative of the respective locations of the damper pivot shafts 25. Of course, where each tube bank 30 includes the bafiles 300, the spacing apart of the shafts 25 will be different in view of the additional obstruction to air flow presented by the baffle web 30d (FIGURES 5-7).

As shown in FIGURES 1 and 4, each heater tube 30a extends between a steam or hot water header 33 at the top of the heater unit and a similar but movable header 34 at the bottom of the unit, the tubes 30a being in flow communication therewith. The headers 33 and 34 are closed at their respective ends and extend horizontally across the width of the unit between their respective mounting feet 22 and 20, the upper header 33 being a fixed header attached to feet 22, and the lower header 34 being vertically movable to accommodate linear thermal expansion of the tube bank 30. Each tube 30a has a right angle bend 37 adjacent its lower end, as shown in FIGURE 4, further to accommodate thermal expansion of the individual tube with respect to any other. Steam or hot water, at high temperature and under pressure, may be admitted either to the lower header 34 or to the upper header 33 via either the lower conduit 35 or upper conduit 36, respectively, whereupon the fluid flows either upwardly or downwardly, as the case may be, through all of the heater tubes 30a to the opposite header from which it is discharged via the other conduit 35 or 3 6.

lhus, air flowing through the face passages 23 will be ieated as it passes over the tubes 30a and fins 30b. Air flowing through the bypass passages 24 will not be heated.

Referring to FIGURES 1-4, it will be noted that the iamper pivot shafts 25, and preferably the tube banks 0 and upper header 33, are aligned within the translersely extending vertical center-line plane of the heater lnit frame 12. Identical damper pairs, respectively composed of the damper wings 26, 27 and 28, 29, are mount- :d on respective pairs of the shafts 25 as shown, each pair of damper wings 26, 27 extending outwardly and :ontrolling air flow at the end 19 of the heater unit, and :achpair of damper wings 28, 29 extending outwardly and controlling air flow at the other end 18 of the unit. Although the air through the heater unit 11 may flow 11 either direction with equal results, for purposes of lescription the end 18 will be referred to as the air inlet and, and the end 19 will be referred to as the outlet end pf the heater, considering the direction of air flow to be hat as indicated by arrows A in FIGURES 2 and 3. Accordingly, the damper pairs composed of wings 28, 29 will be referred to as the inlet dampers, and the damper pairs composed of wings 26, 27 as the outlet dampers. When all of the damper wings have been pivoted in the respective directions of arrows B to their positions as ihown in FIGURE 2, the face passages 23 are fully open and the bypass passages 24 are fully closed so that all )f the air passing through the heater unit 1.1 will pass )ver and be heated by the heater tube banks 30 within :he face passages 23. When the damper wings have been pivoted in the respective directions of arrows C to their positions as shown in FIGURE 3, the face passages 23 are fully closed and the bypass passages 24 are fully open i that all of the air passing through the heater unit will pass through only the bypass passages 24 and will not pe heated. As illustrated by dotted line showing in FIG- URE 2, the damper wing pairs 28, 29 and 26, 27 are also iymmetrically and concurrently positionable at any internediate position between those shown in full lines in FIGURES 2 and 3 so that the total flow of air through he heater unit 11 may be selectively proportioned par- :ially through the face passages 23 and partially through he bypass passages 24. Its downstream temperature s thereby modulated by heating only a predetermined lolume of the total air flow.

Referring now to the construction, arrangement, and pperation of the air flow dampers of the preferred embodiment as shown in FIGURES 14 and 8-10, the respective wings 28, 29 of each inlet damper pair pivot in opposite iirections and concurrently to the same extent, in the respective directions of arrows B and C, when opening (FIGURE 2) and when closing (FIGURE 3) their associated face passage 23. The same is true regarding the respective wings 26, 27 of each outlet damper pair at the )pposite end of the face passages. Moreover, all of the putlet damper wings 26, 27 pivot concurrently with, and ;o the same extent as all of the inlet damper wings 28, 29, so that the inlet and outlets ends of any face passage 23 are, at any given damper positioning, opened or closed to an equal extent. Of course, with respect to any bypass passage 24, the adjacent damper wings which will close :he passage are also characterized as being pivotable in ppposite directions so that for purposes of description it may be said that, considered together, all of the damper wings across the width of the unit (at either its inlet end [8 or its outlet end 19) are pivotable in alternately opposite directions.

As illustrated, the respective wings in any pair of inlet damper wings 28, 29 or outlet damper wings 26, 27 are iymmetrically configured with respect to each other so hat their correlated action in closing and opening their associated face and bypass passages may be characterized 13 that of a clam shell. Actually, all of the wings are identically configured, but the alternate adjacent wings are simply inverted at the time of mounting to achieve the desired symmetrical effect. Each damper wing is formed from an initially flat and elongated piece of sheet steel by simple longitudinal curving or bending operations. In its preferred embodiment, the wing has angular cross-sectional configuration as most clearly indicated in FIGURES 2. and 3. That is, and considering each damper wing in outward direction from its hinged end, it has a longitudinally extending bend 38 defining a hinged end portion (26a, 27a, 28a, or 29a) closely adjacent to its otherwise free edge; an oppositely directed, longitudinally extending bend 39 at a location substantially midway of the depth of the wing which defines an inner wing portion (26b, 27b, 28b, or 2%) and an outer wing portion (260, 27c, 280, or 29c), the included angle between these wing portions being and an inwardly turned free end of the wing formed by a longitudinally extending right angle bend 40, in the same direction as the bend 39, and which defines a wing surface portion (26d, 27d, 28d, .or 29d) as shown. Actually, and as required for descriptive purposes, each inner wing portion 26b, 27b, 28b, 2% may be said to include its associated hinged end portion 26a, 27a, 28a or 29a, respectively, and each outer wing portion 26c, 27c, 280 or 290 may be said to include its associated wing surface 26d, 27d, 28d or 29d, respectively.

p The angular configuration of each damper wing as defined by its bend 39 is such that it abuts against the respective of its adjacent, symmetrically configured wings in its respective positions both fully closing the face passage 23 or the bypass passage 24 with which it is associated. That is, in the bypass passage closed position .of the dampers as illustrated in FIGURE 3, the surfaces of the outer wing portions 260, 27c, or 280, 29c, as the case may be, of the laterally adjacent damper wings within any bypass passage 24 are in abutting cofacing relation with each other to further reduce air leakage, the plane of their interface being perpendicular to the plane of alignment of the shafts 25, so that the bypass passage is fully closed. In the face passage fully closed position of the dampers as illustrated in FIGURE 3, the extreme outer edges of the wing surface portions 26d, 27d or 28d, 29d, as the case may be, of the laterally adjacent damper wings which are now positioned within any face passage 23 are in substantially abutting relation with each other so that the face passage is fully closed. In the latter position, the inner wing portions 26b, 27b, 28b and 29b are disposed perpendicular to the plane of the shafts 25, so that the bypass passages are fully open.

However, it will be noted that, in the FIGURE 3 position, a longitudinally extending sealer element 41 attached to one of the wings and having triangular cross-sectional configuration corresponding to the angular relationship between the cofacing surface portions 26d, 27d, or 28d, 29d, as the case may be, provides respective surfaces 41a, 4117 which actually effect the abutting relation of the pair .of damper wings. Each sealer element 41 extends the full height of the wing to which it is attached, and is made of appropriately bent, soft metal such as 16-gauge cold rolled steel. As is the filler stripping 32, the sealer 41 is hammered to close-fitting relation between its associated wings at the time of installation of the heater unit 11.

In its preferred embodiment, the triangular sealer element 41 includes a spring clip portion 410 for its tight fitting but somewhat flexible or slidable attachment to the end edge of one of the wings of either the inlet damper pair or the outlet damper pair with which it is associated. Its inwardly turned surface 41b is intended to be in abutting cofacing relation with the free end surface of the adjacent damper as illustrated in FIGURE 3, and it will be noted that its spring-clip connection to the first damper wing facilitates achievement of a close fitting of the sealer element between the damper wings during the fit-up operation.

In an alternative embodiment as shown in FIGURE 5, the flexible sealer element may be in the form of a rod 42 having a flange 43 by which it is attached, as by screws 44, along the length of one of the wings .of the damper pair. The cold rolled steel attachment flange 43 and rod 42 are deformable so that the sealer element may be accurately positioned to fully seal the dampers in their closed position, as in the preferred embodiment.

The alternative damper wing configuration, as illustrated in FIGURES 6 and 7, avoids the necessity for inclusion of a sealer element such as element 41 or 42. That is, each damper wing of the inlet damper pair 45, 46 or outlet damper pair 47, 48 has hollow, rectangular parallelogram configuration in cross-section, as shown. The inner wing portion (respectively 45a, 46a, 47a and 48a) by which the Wing is pivotally connected to its associated fixed pivot shaft 25, is formed in part by one of the innermost pair of conjoining surfaces provided by the parallelogram configuration. It will be noted that the remaining length of the inner wing portion, which may include an angular bend (unnumbered) as shown), additionally serves to displace its associated outer wing portion (respectively 45b, 46b, 47b and 48b) outwardly from its pivot shaft 25 for clearance of the tube bank 30 when the damper pair is in its closed position as shown in FIGURE 6. It will be noted that the acute angle 49 within any of the rectangular parallelogram shaped wings is equal to the angular distance of pivotal movement of the wing in moving between its face passage fully closed position as shown in FIGURE 6 and its bypass passage fully closed position as shown in FIGURE 7. Thus, the wing surface 50, which is one of the outermost pair of conjoining surfaces provided by the parallelogram configuration, cofacingly abuts the symmetrical, corresponding edge surface 50 of its adjacent wing in their contacting positions closing a bypass passage 24 as seen in FIG- URE 7. When the damper wings are pivoted oppositely to their positions closing their associated face passages 23 as shown in FIGURE 6, each wing surface 51, which is the other of the outermost pair of conjoining surfaces, cofacingly abuts the symmetrical, corresponding slant edge surface 51 of the wing with which it is now associated. Of course, the spacing within the tubular shaped wings may be filled with heat-insulating material (not shown) or not, as circumstances may dictate for good thermal insulation when the face passages 23 are intended to be fully closed. The concurrent, alternately opposite pivotal movement of the dampers of the FIG- URES 6 and 7 embodiment is the same as that of the preferred embodiment.

Referring again to FIGURE 1, concurrent and alternately opposite movement of the laterally adjacent inlet damper wings 28, 29 is induced by simultaneous movement in respectively opposite directions of the pair of horizontally disposed damper wing connecting bars 52 and 53, a similar pair of connecting bars 54, 55 (FIG- URES 2 and 3) being provided at the outlet end 19 of the unit for controlling the similar movement of the outlet dampers 26, 27. Although more than one such pair of connecting bars might be employed for controlling the dampers on either end of the unit (for example, along the top and bottom of the group of wings), it has been found that only one such pair of connecting rods, connected along the mid-points of the respective damper wings as shown in FIGURE 1, will adequately serve the purpose.

The connecting bar 52 is pivotally connected by respective vertical hinge pins 56 to each of the damper wings 29, whereas the connecting bar 53 is similarly connected only to the damper wings 28 by respective hinge pins 57, as shown. Similarly, at the other end 19 of the heater unit, the connecting bar 54 is pivotally connected by hinge pins 58 to each of the damper wings 27, and the connecting bar 55 is hingedly connected only to the wings 26 by the respective pins 59. The pin connections of these connecting bars to the outwardly facing free ends of the respective damper wings are actually made, respectively,

to the end of an outwardly projecting pivot bar which is securely attached to each damper wing. The pivot bars of each of the damper wings 26, 27, 28 and 29 are respectively indicated by reference numerals 60, 61, 62 and 63. Detailed illustration of these pivot bars has been omitted from FIGURES 2 and 3 for clarity, but is included in FIGURE 9. That is, each of the pivot bars 60-63 is made of relatively heavy metal and extends inwardly through respective slots (unnumbered) in both the inwardly turned end surface portion and the inner wing portion of the wing to which it is attached, each bar having an arcuately curved inner portion, respectively 60a, 61a, 62a, and 63a, the inner end of which is apertured for hinge connection to the pivot axis 25 on which the wing is mounted. The pivot bars are attached along their inwardly extending lengths, as by welding, to form an integral part of the respective damper wings. It will be understood that similar damper control pivot bars are attached to the modified forms of damper wings shown in FIGURES 5-7.

Because the respective damper wings 27, 29 at the opposite ends 18, 19 of the unit are intended to move in unison in the direction of arrows B and C (FIGURES 2 and 3), their respective connecting bars 52, 54 will have concurrent and identical movement in the same direction either to the right or to the left as seen in FIGURES 1-3, 8 and 9. For simultaneously pivoting the respectively opposite damper wings 26, 28 in opposite direction, their connecting bars 53, 55 will be concurrently moved in direction opposite to that of connecting bars 52, 54, the movement of all of the connecting bars being simultaneous and to the same extent.

Such concurrent and opposite movement of connecting bars 52, 54 and 53, 55 is effected by means of a drive assembly 64 which is operated by a Minneapolis-Honeywell No. M4E reversible motor (not shown) via a vertically movable drive lever 65, the distance of stroke of the lever 65 being 4 in the illustrated embodiment. If two such motors are employed, the second motor will concurrently drive the mechanism via a second drive lever as illustrated by dotted line showing 66 in FIGURE 10. The requisite 45 angular distance of movement of each damper wing 26, 27, 28, 29 in moving between its face passage closed and bypass passage closed positions (see FIGURES 2 and 3) is achieved upon full, 45 angular movement of the vertically pivotable pair of crank arms 67, 68, the drive lever 65 being pivotably connected, as at 65a, to the arm 67. If included, the second drive lever 66 would be pivotably connected as at 66a to the crank arm 68. The pair of crank arms 67, 68 are respectively attached at the opposite ends of a horizontally disposed pivotable shaft 69 which spans between, and is rotatably mounted on fixed brackets 70, 71, the crank arms being movable between their identical face passage opened positions wherein their respective lower arms are disposed 22% above the horizontal (illustrated in FIGURES 1 and 8) over an arc of 45 in counterclockwise direction to their identical face passage closed positions (not shown) wherein their respective lower arms are disposed 22 /2 below the horizontal. The brackets 70, 71 are actually an integral part of a cast iron drive assembly frame 72 which is attached, as by bolts 73, to the respective flanges 13a of the vertical side 13 of the frame 12, as more clearly illustrated in FIGURES 8-10.

The drive assembly frame 72 includes a laterally projecting bracket 74 at the outer end of which there is attached a vertically disposed shaft 75 whose ends project upwardly and downwardly from the bracket as shown. An upper lever 76 is mounted for pivotal movement, at a location midway along its length, on the upper end of the shaft 75, and a lower lever 77 is similarly mounted for independent pivotal movement on the lower end of the shaft 75, the lever mountings being retained by the respective mount washers 78, 79. In the face passage open position of the inlet and outlet dampers as shown in FIG- URES 8 and 9, the levers 76 and 77 are displaced with respect to each other an angular distance of 45 as seen in their horizontally projected plane (FIGURE 9). Referring to FIGURES 8-10, the damper wing connecting bar 52 is pivotably connected, via an operating bar 52a, to one of the ends of the upper lever 76, the operating bar 52a being passed through an aperture 80 (FIGURE 10) formed through the frame 13 and drive assembly frame 72. The pivot connection to the lever 76 is by a pivot pin 81 and, at its opposite end, the operating bar 52a is pivotably connected to the connecting bar 52 via a universal ball joint 82. Similarly, the connecting bar 53 at the same end 18 of the heater unit is pivotably connected to the corresponding end of the lower lever 77, the connection being via its operating bar 53a which passes through a similar frame aperture 83. Connection of the bar 53a to the arm 77 is via a pivot pin 84, and its pivotable connection to the bar 53 is via a universal ball joint 85, as shown. Thus, upon opposite pivotal movement of the arms 76 and 77, each over their maximum angular distance of 45, the pairs of inlet damper wings 28, 29 will be pivoted from their face passage full open positions, as shown in FIGURES 2, 8 and 9, to their face passage fully closed position as shown in FIGURE 3. Opposite pivotal movement of the levers 76, 77 will, of course, pivot the damper wings 28, 29 to reopen the face passages 23.

The pairs of outlet damper wings 26, 27 at the opposite end 19 of the heater unit are controlled by similar connections between their respective connecting bars 55, 54 to the opposite ends of the levers 76 and 77. However, because the outlet damper wing 27 is intended to pivot in direction opposite to that of the inlet damper wing 29 which is mounted on the same pivot shaft 25, its connecting bar 54 is pivotably connected via its operating bar 54a to the opposite end of the lower lever 77 as at hinge pin 86, the operating bar 54a having ball joint connection (not shown) at its opposite end to the connecting bar 54. The operating bar 54a passes through an appropriately located frame aperture 87, as seen in FIGURE 10. In like manner, and so that the outlet damper wings 26 will pivot concurrently with, but in opposite direction with respect to the inlet damper wings 28 which are pivotable on the same shaft 25, the connecting bar 55 (to which the wings 26 are attached) is pivotally connected, via its operating bar 55a, to the opposite end of the upper lever 76 at hinge pin 88. As seen in FIGURE 10, the operating bar 55a passes through a suitable frame aperture 89.

To effect the simultaneous, opposite angular movement of the levers 76 and 77, a link rod 90 connects the upper leg of the crank arm 67 to the upper lever 76, and a similar link rod 91 connects the upper leg of the other crank arm 68 to the lower lever 77. The link rods 90 and 91 are pivotably connected at one of their ends to the respective crank arms, these connections being respectively designated by reference numerals 90a and 91a. At the1r opposite ends the link rods are pivotably connected, at respective connections 90b, 91b to the projecting ends of respective, vertically disposed slide followers 92, 93 which, at their upper ends, are slidable within the axially aligned slots 94, 95 of the upper lever 76 and the lower lever 77 respectively. Thus, downward movement of the drive lever 65 will pivot both crank arms 67, 68 to an equal extent in counterclockwise direction as seen in FIG- URE 8 whereupon, as viewed in FIGURE 9, the upper lever 76 will pivot in clockwise direction and the lower lever 77 will pivot in counterclockwise direction. Upward movement of drive lever 65 will pivot the crank arms and levers in opposite direction. The maximum distance of pivotal movement of the crank arms 67, 68 and levers 76, 77 between the full open and full closed positions of the dampers is 45 as aforesaid, although it will be understood that, by suitable drive motor controls (not shown), their movement in either direction may be stopped at any intermediate position so that the inlet and outlet dampers may be intermediately positioned to retain both the face passages 23 and bypass passages 24 in partially opened condition. At such intermediate positions of the dampers, the total air flow through the heater unit 11 will be proportioned between the face and bypass passages to modulate the downstream temperature of the air, as previously referred to.

As an example of the operating results obtained by the present invention, the referred to temperature override through the air heater unit 11 is only three degrees (3 F.) during highest temperature operation as compared with a minimum of twenty degrees (20 F.) temperature override obtainable by the referred to Horn etal. air heater under the same operating circumstances.

Thus has been described an air heater having dampers which achieve all of the objects of the invention.

What is claimed is: I

1. Apparatus for conditioning a flow of fluid therethrough, comprising a plurality of parallel extending shaft means in laterally spaced apart relation with each other to thereby define alternate and laterally adjacent fluid conditioning passages and bypass passages for passage of :said flow of fluid through the plane of alignment of said shaft means, fluid conditioning means within each said fluid conditioning passage, damper means comprising a corresponding plurality of damper wings each having substantially angular cross-sectional configuration providing an inner end portion and an outer end portion thereof and being respectively mounted, substantially along the otherwise free edges of their said inner end portions, for pivotable movement on the respective of said shaft means whereby each said damper wing is pivotable between a first position wherein its said outer end portion is disposed within its adjacent fluid conditioning passage and a second position wherein its said outer end portion is disposed within its adjacent bypass passage, all of said damper wings projecting generally in the same direction outward from said plane of the shaft means and said angular configurations of the damper wings in any adjacent pair thereof being symmetrical with respect to each other, and damper control means for concurrently and reciprocally pivoting all of said damper wings between their said respective first and second positions and in alternately opposite directions with respect to each other, whereby said damper means concurrently and at least partially closes all of said fluid conditioning passages while proportionately opening of all of said bypass passages, and concurrently and at least partially closes all of said bypass assages while proportionately opening all of said fluid conditionmg passages.

2. Apparatus according to claim 1 wherein said outer end portion of each damper wing extends substantially half-way across the width of said adjacent fluid conditioning passage when the damper wing is in its said first position, said outer end portions of each pair of damper wings adjacently associated with any said fluid conditionmg passage thereby being substantially in abutting relation with each other when the damper wings of the pair are in their said finst positions, whereby said damper means is positionable to concurrently and fully close all of said fluid conditioning passages.

3. Apparatus according to claim 2 wherein said outer end portion of each said damper wing includes an inwardly turned free end in the direction of its said adjacent fluid conditioning passage, and said apparatus further comprises sealer strip means substantially attached to one of said damper wings of said pair adjacent the surface thereof which is defined by said inwardly turned free end of its said outer end portion, said sealer strip means being disposed with respect to the other damper wing of said pair such that, when the damper wings of said pair are in their said first positions, said sealer strip means is in closely fitting engagement with that surface of said other damper wing which is defined by said inwardly turned free end of its said outer end portion.

4. Apparatus according to claim 3 wherein said sealer strip means comprises a sealer strip having substantially triangular cross-sectional configuration presenting a pair of surfaces in angular disposition with respect to each other, said surfaces being respectively in cofacing abutting relation with the respective of said surfaces defined by said inwardly turned free ends of said pair of damper wings when the latter are in their said first positions.

5. Apparatus according to claim 3 wherein said sealer strip means comprises substantially flexible rod means extending substantially along said surface defined by said inwardly turned free end of the damper wing to which it is attached.

6. Apparatus according to claim 2 wherein said inner end portion of each damper wing is disposed within and extends substantially half-way across the width of said adjacent bypass passage when the damper wing is in its said second position, said inner end portions of each pair of damper wings adjacently associated with any said bypass passage thereby being substantially in abutment with each other when the damper wings of the pair are in their said second positions, whereby said damper means is further positionable to concurrently and fully close all of said bypass passages.

7. Apparatus according to claim 6 wherein said outer end portion of each damper wing is substantially flat and extends substantially perpendicular to said plane of the shaft means when the damper wing is in its said second position, whereby said outer end portions of each said pair of damper wings adjacently associated with any said bypass passage are in substantially cofacing abutting relation with each other when the damper wings of the pair are in their said second positions.

8. Apparatus according to claim 7 wherein the arc of said pivotable movement of each said damper wing is substantially forty-five degrees (45), said inner end portion of each damper wing being substantially flat and extending substantially perpendicular to said plane of the shaft means when the damper wing is in its said first position and being disposed within said adjacent bypass passage at an angle of substantially 45 with respect to said plane of the shaft means when the damper wing is in its said second position.

9. Apparatus according to claim 7 wherein the crosssectional configuration of each said damper wing is substantially that of a parallelogram having acute angles respectively equal to the arc of pivotable movement of the damper wing between its said first and second positions and respectively providing an innermost pair and an outermost pair of conjoining surfaces of the damper wing, said inner end portion of the damper wing comprising one of the surfaces of said innermost pair of surfaces, and said outer end portion of the damper wing comprising said outermost pair of surfaces whereby, with reference to each said pair of damper wings adjacently associated with any said fluid conditioning passage, that one of said outermost pair of surfaces opposite said one of the innermost pair of surfaces of the damper wing is in substantially cofacing abutting relation with the same corresponding surface of the other of said pair of damper wings when the damper wings of the pair are in their said first positions.

10. Apparatus according to claim 9 wherein each said acute angle is substantially forty-five degrees (45 11. Apparatus according to claim 1 which further comprises second damper means comprising a corresponding plurality of damper wings each having substantially angular cross-sectional configuration providing an inner end portion and an outer end portion thereof and being respectively mounted, substantially along the otherwise free edges of their said inner end portions, for pivotable movement substantially on the respective of said shaft means whereby each said damper wing of said second damper means is also pivotable between a first position wherein its said outer end portion is disposed within its adjacent fluid conditioning passage and a second position wherein its said outer end portion is disposed within its adjacent bypass passage, all of said damper wings of said second damper means projecting generally in the same but opposite direction outward from said plane of the shaft means whereby the first said damper means and said second damper means are respectively disposed at opposite ends of said apparatus, said angular configurations of the damper wings of said second damper means in any adjacent pair thereof also being symmetrical with respect to each other, said damper control means including means for concurrently and reciprocally pivoting all of said damper wings of said second damper means between their said respective first and second positions and in alternately opposite directions with respect to each other, whereby said second damper means concurrently and at least partially closes all of said fluid conditioning passages while proportionately opening all of said bypass passages, and concurrently and at least partially closes all of said bypass passages while proportionately opening all of said fluid conditioning passages, said pivoting of the damper wings of said second damper means being substantially concurrent with said pivoting of the damper wings of the first said damper means and to substantially the same extent, whereby said flow of fluid through said apparatus may be received from either direction.

12. Apparatus according to claim 11 wherein said plurality of shaft means comprises a row of single shafts, each said single shaft having one damper wing of the first said damper means and one damper wing of said second damper means mounted for said pivotable movement thereon.

13. Apparatus according to claim 12 wherein said damper wings mounted on each said single shaft have filler stripping means in close-fitting relation to the shaft for providing heat-shielding between said fluid conditioning passage and the adjacent bypass passage with which the shaft is associated.

14. Apparatus according to claim 12 wherein said fluid conditioning means within each said fluid conditioning passage comprises heater tube means disposed substantially within the plane of alignment of said row of single shafts.

15. Apparatus according to claim 11 wherein said damper control means comprises a pair of pivotable levers mounted on a common axis of pivotable movement extending through the midpoints of their respective lengths, first connecting means comprising a pair of damper connection bars one of which is hingedly connected to each of those damper wings of the first said damper means which pivot in one direction and the other of which is hingedly connected to each of those other damper wings of the first said damper means which pivot in the opposite direction, second connecting means comprising a second pair of damper connection bars one of which is hingedly connected to each of those damper wings of said second damper means which pivot in one direction and the other of which is hingedly connected to each of those other damper wings of said second damper means which pivot in the opposite direction, one of said connection bars of each said pair thereof being respectively connected to each of the opposite ends of one of said levers, and the other conection bar of each said pair thereof being respectively connected to each of the opposite ends of the other of said levers, and means for concurrently pivoting both said levers in opposite dirctions with respect to each other.

16. Apparatus according to claim 15 wherein said pair of levers are disposed in arcuately spaced apart relation with respect to each other when said damper wings are in their said first positions, the angle of said arcuate spacing being substantially equal to the arc of said pivotable movement of each of said damper Wings, all of said damper wings being pivotable to the same extent, said levers being pivotable between respective positions 15 )n opposite sides of the imaginary plane which bisects said angle of arcuate spacing between them.

17. Apparatus according to claim 16 wherein said iamper control means further includes crank arm means mounted for pivotable movement, linkage means connecting said crank arm means to one of said levers for imparting said pivotable movement to the latter responsive to pivotal movement of said crank arm means, and second linkage means connecting said crank arm means to the other of said levers for imparting said opposite pivotal movement to the latter responsive to the same pivotal movement of said crank arm means.

18. Apparatus according to claim 11 wherein all of said damper wings of the first said damper means and said second damper means have identical cross-sectional configuration and construction, whereby each said damper wing is interchangeable with any other.

References Cited UNITED STATES PATENTS 3,107,724 10/1963 Horn et a1. 165-103 ROBERT A. OLEARY, Primary Examiner C. SUKALO, Assistant Examiner US. Cl. X.R. 16596, 103 

